1. Field of Invention
The present invention relates to a DC-AC frequency converter type mucus suction device for removing things from the inside of the nose of a user, and more particularly relates to a mucus suction device with an electromagnetic pump supplied with AC obtained from the oscillation of DC, herein the speed, frequency, and amplitude of the swinging of the swing arms of the electromagnetic pump vary with the frequency of the switching between the N-phase and S-phase of the electromagnetic device, so that the suction pressure and the suction flow generated in the electromagnetic pump will satisfy the requirement of the mucus suction device.
2. Description of Related Arts
Referring to FIGS. 1-7, an electromagnetic pump 20 is disclosed, which could also be called as a swing arm pump or a matrix type pump. The electromagnetic pump 20 is light in weight and could be operated with less noise, lower power consumption and less chance to generate high heat, and the electronic circuit of the electromagnetic pump is hard to start when the inlet and the outlet channels are blocked. Considering these shortcomings, the applicant of the present invention adopted the electromagnetic pump as the power source of the electric nose suction device claimed in the Taiwan patent application No. 093217312 filed in 2004, in which the electromagnetic pump 20 has an electromagnetic device 27 on one side and a pump housing 21 on the other side. Each of two outer opposing sides (or one can say opposing members) of the pump housing 21 provides a stretchable and elastic hat 24, which further provides a swing arm 25 respectively thereon, wherein one end of each swing arm 25 is disposed on the outer side of the pump housing 21 and a magnetic member 26 is provided on the other end of each swing arm 25 at a site remote from the electromagnetic device 27. The inside of the pump housing 21 is divided into two chambers 211 and 212, wherein the first chamber 211 is communicated with two inlet tubes 22 and the second chamber 212 is communicated with two outlet tubes 23. Referring to FIGS. 2 and 3, the electromagnetic device 27 has two side magnetic members 271 and a middle magnetic member 272, wherein the magnetism of the three members alternate between N-phase and S-phase. The two magnetic members 26 are disposed opposite to the two side magnetic members 271 respectively and have N-phase outside surfaces and S-phase inside surfaces respectively. As shown in FIG. 2, when the two side magnetic members 271 of the electromagnetic device 27 switch to N-phase and the middle magnetic member 272 switches to S-phase, the two magnetic members 26 are attracted by the middle magnetic member 272 and repulsed by the two side magnetic members 271 to bring the swing arms 25 towards the middle. In contrast with FIG. 3, when the two side magnetic members 271 of the electromagnetic device 27 switch to S-phase and the middle magnetic member 272 switches to N-phase, the two magnetic members 26 are repulsed by the middle magnetic member 272 and are attracted by the two side magnetic members 271 to bring the swing arms 25 towards the outside. The speed, frequency and amplitude of the swinging of the swing arms are relative to the predetermined frequency of the power source, and also relative to the suction pressure and the suction flow. Referring to FIGS. 4-7, when the swing arms 25 swing towards the outside to expand the hats 24 respectively, the two first check valves 241 respectively provided between the pump housing 21 and the hats 24 are set to open to allow fluid flow into the first chamber 211 through the inlet tubes 22 on the outside of the pump; the fluid flows into the two hats 24, and then is stopped from flowing into the second chamber 212 by two second check valves 242, as the two second check valves 242 are turned off. And when the two swing arms 25 swing towards the middle to compress the two hats 24 respectively, the two second check valves 242 are turned on and the first check valves 241 are turned off, hence the fluid in the two hats 24 could only flow into the second chamber 212, but reflow back into the first chamber 211, substantially the fluid in the second chamber 212 is discharged from the pump housing 21 through the two outlet tubes 23. With the designs mentioned above, the pump housing 21 draws a fluid from the inlet tubes 22 and then discharges the fluid from the outlet tube 23 to accomplish the transporting of the fluid. As shown in FIG. 8, the inlet tubes 22 connect to a suction device 80, so that the suction device 80 could be used to draw mucus.
The electromagnetic pump 20 must be supplied with AC to drive the two swing arms 25—back and forth. However, as the voltage of the domestic electricity used in the countries worldwide is 110V or 220V, for example, the domestic electricity in Taiwan is single phase electricity with a voltage of 110V and a frequency of 60 HZ. When alternating electricity of 110V and 60 HZ is used as the power source of the electromagnetic pump 20, the speed, frequency and amplitude of the swinging of the swing arms 25 of the electromagnetic pump 20 are fixed and could not be adjusted due to a combined effect of the magnetic field strength generated in the electromagnetic device 27, the length and width of the swing arms 25, the magnetic strength of the magnetic members 26, and the elasticity of the hats 24. That means the pressure and the flow of the suction, or the pressure and the flow of the discharge of the electromagnetic pump 20 could not be adjusted according to the requirement of the pressure and/or the flow. Hence, when the electromagnetic pump 20 is used to draw the mucus, the suction force might be so large to cause damage to the nasal mucosa, or be too small to draw the mucus off. Hence, the electromagnetic pump 20 needs to be improved.